Periosteal ganglion cyst
Periosteal ganglion cysts or periosteal ganglia are a rather rare type of ganglion cysts which affect the periosteum.
Clinical presentation
Clinical symptoms depend on the location, they have been reported to present with pain, as a firm, painless swelling and were found incidentally.
Pathology
Periosteal ganglion cysts are well-defined, smooth-walled, cystic masses of the periosteum. Similar to other ganglion cysts they are filled with clear, mucinous material and lack a synovial membrane.
Etiology
They are thought to be a consequence of mucoid degeneration of the periosteum .
Location
Most commonly they are located in the proximal diaphysis of the tibia near the pes anserinus, other locations affect the other long bones e.g. the femoral intercondylar region, the metatarsal bones or tarsal tunnel .
Radiographic features
Plain radiograph
Plain radiographs may show superficial scalloping or cortical erosion as well as signs of reactive bone formation
MRI
MRI is the best modality for the visualization and evaluation of periosteal lesions . The typical appearance is that of a well-defined cystic mass arising from the periosteum .
- T1: will depend on protein content, but mostly hypointense
- T2: hyperintense
- PDFS/T2FS: hyperintense
Treatment and prognosis
Management options depend vastly on clinical symptoms and location and include conservative measures, image-guided percutaneous aspiration as well as surgical excision .
History and etymology
First descriptions of periosteal ganglion cysts were apparently made by Ollier in 1864 and Poncet in 1874 .
Differential diagnosis
Conditions which can mimic the presentation and/or the appearance of periosteal ganglia include :
- subperiosteal hematoma
- chronic subperiosteal abscess
- periosteal aneurysmal bone cyst
- hydatid cyst
- periosteal chondroma
- malignant soft tissue tumors